Pneumatic dispatch system



Nov; 5, 1935. c. s. JENNINGS ET AL PNEUMATIC DISPATCH SYSTEM Filed Nov. 1, 1932 8 Sheets-Sheet 1 NN Q K A M. Na K NR N MN RN N q MN NM Nov; 5, 1935. 'c. 5. JENNINGS ET AL I a' a PNEUMATIC DISPATCH SYSTEM Filed Nov. 1, 1932 a Sheets-Sheet 2 63. I fiwerzzors kaslerJfimzilQ's z uzk Mae-1% a 15W v v w.

Nov. 5, 1935'. c. 5. JENNINGS ET AL 2,019,361

PNEUMATIC DISPATCH SYSTEM Filed NOY. l, 1952 8 Sheets-Sheet 3 121x15 Wj'facfllarl Wya- Nov. 5, 1935. t c. 5. JENNINGS ET AL' PNEUMATIC DI SPATCH' SYSTEM Filed Nov. 1, 1932 s Sheets-Sheet 5 fiwarziors kesi'frniofemal s 7* WEI 1 1a '1? WV% r I NOV. 5, 1935. c, 3 JENNINGS r AL 2,019,861

PNEUMATIC DI SPATCH SYSTEM Nov. 5, 1935. c. 5. JENNINGS ET AL 2,019,861

PNEUMAI'IC DISPATCH SYSTEM Filed Nov. 1, 1932 8 Sheets-Sheet '7 5.75 7f STATION A &1

STATION B j7werzzams 'iaasieri Jfirzizilgys raw Hi a Mr/ZjZ Nov. 5, 1935. c. 5. JENNINGS El AL 2,019,861

PNEUMATIC DISPATCH SYSTEM Filed Noy. l, 1932 Y 8 Sheets-Shea), 8

Patented Nov. 5, 1935 UNllED STATES PNEUMATHC DISPATCH SYSTEM Chester S. Jennings and Frank W. MacMartin, Syracuse, N. Y., assignors to The Lamson Com-.

pany, Syracuse, N. Y.,

ohusetts a corporation of Massa- Application November 1, 1932, Serial No. 640,624

20 Claims.

This invention relates to an improvement in a pneumatic dispatch system and more particularly in one of the single transit tube type being 7 a further development and modification in certain respects upon the system disclosed in the patent to Jennings No. 1,861,964, dated June 7, 1932 and the patent to Jennings and MacMartin No. 1,871,995, dated August 16, 1932.

Systems of this type are particularly adapted for long line tube systems as for example in railroad yards where the terminals are several thousand feet apart. Since a single transit tube is used it is obviously necessary to avoidthe possibility of collision due to the dispatch of a carrier from one terminal when a carrier is already in transit from the other terminal. As disclosed in the patents above referred to such occurrence is avoided by electrical control.

One object of the present invention is to simplify the electrical control heretofore thought to be essential whereby, without impairing the various important and necessary features of the earlier systems, the number of Wires running between the terminals is reduced to a minimum, three or two being found all that are necessary; and the initial control is from a single source at one station only, the source at the other station bearing no direct relation whatsoever to the source at the first station but being. controlled by relays actuated by the initial control.

Another object of the invention is to provide means for actuating and interlocking the valves at the terminals, such means being either pneumatically operated in conjunction with the air transmitting flow set up in the system or positively operated concomitantly with the set up of such air flow.

A further object of this invention is to pro vide at the terminals of the systems, air and 40 electrical control devices which are operated simultaneously whereby electrical circuits are completed which set up a carrier transmitting" I Fig. 3 is a side elevation of such valve control unit;

' Fig. 4 is a sectional view illustrating one o the valves, the clapper being shown in full lines in the open position and in dotted lines in the 5 closed position;

Fig. 5 is a sectional view taken along the line 55 of Fig. 4; r

Fig. 6 is a diagram illustrating one form of Wiring which might be employed with the em- 10 bodiment shown in Figs. 1 to 5;

Fig. '7 is a side elevation of a terminal embodying another form of this invention;

Fig. 8 is an enlarged view of one element of that terminal; 15 Fig. 9 is a view of such element with parts broken away;

Fig. 10 is a diagram illustrating one form of wiring which might be employed with the embodiment shown in Figs. '7, 8 and 9; and

Fig. 11 is a diagram showing another'form of wiring which might be so employed.

It will be understood that the system comprises two terminals connectedby a single transit tube and that since the terminals are similar in con- 25 struction and operation only one terminal of each embodiment has been shown and will be described in detail.

As shown in Fig. 1, each dispatch terminal 15 comprises a plurality of tube sections terminating in a receiving chute 16 of the open type which leads to a receiving trough or pan H. The tube sections here shown comprise lengths 18, I9, 20, 2| and 22, sections l9 and 21 of which being identical in construction and including the valve mechanism which will be described later. The section 22 is provided with a cover 23, preferably hinged or otherwise secured in position, and serves as a dispatching inlet.

Supported upon the sections 2! and 22 are a valve control unit 25 and an electrical control unit 26, carried by brackets 21, 28. The control unit 25 may be of any desired type, that disclosed in the Jennings patent above-mentioned being here shown and not therefore here described in detail. It is sufiicient to point out that when carriers are to be dispatched or are in transit from the terminal air is supplied to the unit through a pipe 38 from the source of supply for the carrier transmitting air (not shown), and is conducted therefrom by a pipe 3| leading to the atmosphere. The control unit 25 is connected'to the valve of section 2| by a pipe 32 and to the valve of section l9 by a pipe 33.

Mounted within the casing of the control unit is a rotor actuated by a handle 35. In View of the disclosure in the patent, it will be understood that, when the handle 35 is in the position shown in Fig. 3, air is supplied under pressure to the pipe 33, while the pipe 32 is connected to the atmosphere through the outlet pipe 3|, and that, when the handle is turned 90, as shown in dotted lines on Fig. 3, air is supplied under pressure through the inlet pipe 30 to the pipe 32, and the pipe 33 is connected to the atmosphere through the outlet pipe 3|.

The shaft 36 of the rotor to which the handle 35 is secured, also carries a cam '3'l,the periphery of which bears upon a pin 38 mountedfonreciprocation in a bracket 39. At its lower :end the pin 38 is provided with aset screw 46, the head of which bears upon a lever 41 pivoted at 42 to the bracket 39. The lever carries at its outer end a pin 43, the lower end of which is enlarged to form a button 44 which engages andactuates the electrical control unit .26. A spring 45 surrounding the pin 43 both tends to raise the .lever 4| so that itnormally assumes the position shown in dotted lines in Fig. 3 and also acts as a cushion for the button. The control unit 26 is of the well-known type by which circuits are made or broken, as illustrated diagrammatically in Fig. 6 and since the structure of this element forms no part-of the present invention, it will .not be described in detail.

The valve unitscarried by the sections [9 and 2| are identicalin construction so that'only one is shown in the drawings and will be described in detail, .the upper unitmounted on section 2! having been selected. The section is preferably made in .two parts and 5|, secured together by bolts 52 through abutting flanges 53, 54. Mounted within the part .50 is a valve clapper 55 including a plate 56 pivotallymounted .upon a pin 51 .carried by the flange 53, as "shown particularly in .Fig. 5, a disk 58 of leather, and a shoe 59 of .metal the plate disk and shoe being suitably joined. The valve clapper 55 is .pneumatically actuated in the present instance by a diaphragm 60 enclosed within a two section casing 6| .mounted .upon the part v50 and adapted to divide it into two compartments .62 and 63 in the usual manner. The center of the diaphragm 60 is reinforced by disks 6.5 and 66 and supports .a shaft 61 connected by links 68 to the plate 56. The links 68, as shown particularly in Fig. 4, are pivotally securedat one end to the shaft 61 by a pin 69, and at the other end to the plate 5.6 by a pin 16. The outer end of the shaft 61 extends through a hood 1|.mounted on the casing 6|, and to it is secured a cable .12 passed around a pulley 1.3 .and provided at its outer end with a counterweight .14.

The pipe 32 from the valve control unit 25 leads to the compartment 63 of the housing -6l and the pipe 33 leads to the corresponding compartment of the housing of the lower valve unit on the section l9. Obviously the counterweights act to hold the valves normally open but when air is introduced into the compartment 63 of either valve unit the diaphragm .is forcedto move lntorthe .position shown in dotted lines in Fig. 4, closing the valve and preventing the passage of air or acar-rier .through that section. When the handle 35 is shifted so that the pipe 32 .is connected to the atmosphere through .the ,pipe 3| and no .air is introduced under pressure into the compartment, .the weight .14 .causes the diaphragm to resume its .normal position and open the valve. In order to limit this opening movement of the valve, there is provided a pin 86 which may be surrounded by a cushioning tube 8! and against which the valve plate 56 bears, as shown in Fig. 4,

When a carrier is to be dispatched from a terminal, the handle 35 is thrown int-o the position shown in full lines in Fig. 3, to create a flow of air which causes the lower valve to be closed, while the upper valve remains open. The cover 3 is then raised and the carrier placed in the section 22 from which it descends by gravity past the upper valve and into contact with the closed lower valve. Upon throwing the handle 35 into the dotted line position, the upper valve will then be closed behind the carrier and the lower valve opened so that the carrier will advance into the tube and be transmitted to the other terminal by airpressure.

The operation of the handle 35 also acts through the lever 4| and the elements associated therewith, to actuate the electrical control unit '26 and thereby complete various circuits through which the operation of the motor or blower is controlled. The movement of the valve into the dotted line position causes the control unit 26 to complete a circuit through a time limiting relay which, after a predetermined period has elapsed, will operate to cut ofi the supply of air, usually subsequent to the arrival of the carrier at the receiving trough ll of the destination terminal.

If, while the first carrier is in transit the operator desiresto dispatch other carriers, the operation previously described will be repeated, that is to say, the handle 35 will be returned to the full .line position, closing the lower valve and opening the upper valve, a carrier will then be inserted through the section 22, and the handle 35 will thereafter be returned to the dotted line position, opening the lower valve and closing the upper valve. At the same time the time limit relaywill be reset.

The electrical operations will now be described with particular reference to the diagram in Fig.

6 and'it "will be assumed first that carriers are to be dispatched from station A to station B.

A button 266 within the electrical control unit 26 is depressed by the button of the lever 4| either manually or by throwing the handle 35 to the left as in Fig.3 which completes a primary circuit from the control source at station B through leads 362, 36.3, normally closed switch 234 of relay 205, lead 206, button 266, lead 267, coil 238 of relay .296, lead 2E3, coil 3 of relay 335 and. lead 3H3.

The energizing of the coil 238 of relay 209 closes the normally open switch 213 and thus completes a control circuit from the source at station A through lead 262, switch N3 of relay 209, lead 2M, coil 215 of starter relay '216, leads Zn, 218, emergency switch 2| 9, and leads 220 and H2. A signal circuit at station B completed by the energizing of coil 3 H of the relay 365 and the consequent closing of the normally open switch 336 is traced through leads 362, 2337, switch 336 of relay 365, lead'3'38, signal 339, lead 3 I 8, emergency switch 3l9, leads 320 and 3! 2. The operator at station B is thus advised that the operator at station A has or is about to dispatch carriers. However the primary circuit above mentioned, by energizing the coil 311 of relay 365, has opened the normally closed switch 364 so that the depression-of the button 360 at that station will be without effect.

The energizing of the coil .2 I 50f the starter relay 2I6 closes the normally open switches HI and 223' and completes at station A a holding bypass for the primary circuitand also a power circuit. The holding by-pass begins at lead 303,

through leads 224, and 225, switch 223 ,of starter relay 2I5,,lead 225, normally closed switch 221 of the time limit relay 228, lead 229 to coil 208 of relay 203. The motor 222 is set into motion by the completion of leads 240 through the closure of the switches 22 I. Thus the circuits above described'are, by the holding by-pass, maintained independent of the position of the button 200.

When the button 200 is released as by throwing the handle 35 to the right (see Fig. 3) it completes the following circuit through the time limit relay 228; from lead 202 and switch 2I3, through lead 230, button 200, lead 232, solenoid unit 233, leads 234, 235 and 2 I8, emergency switch 2 I3, and leads 220 and H2. The solenoid unit 233 acts in the well known way after a predetermined interval to open the switch 22! and break the holding by-pass of. the primary circuit whereupon the other circuits are broken and the system is at rest.

When dispatching in the opposite direction from station B to station A corresponding circuits are completed. The depression of the button 300 completes a primary circuit from the source at station B through leads 302, 303, and 224, coil 2 of relay 205, lead 3"), coil 308 of relay 309,1ead button 300, lead 306, switch 304 of relay 305, and leads 324, and 3I2. The coil 308 of relay 309 closes the normally open switch 3| 3 and completes a control circuit at station B through lead 302, switch 3I3, lead 3M, coil 3I5 of the starter relay 3E5, leads 3H and till, emergency switch 363 and leads 320 and 3I2. The signal circuit at station A is completed by the energizing of the coil 25! of relay 205 which closes the normally open switch 235 and is traced through leads 202, and 231, switch 235 of relay 205, lead 238, signal 239, lead 2 I8, emergency switch'2 I0 and leads 220 and 2I2. The energizing of the coil 3I5 of the starter relay 3I5 by the control circuit at station B closes switches 323' and 32! and completes a. holding by-pass through lead 329, switch 321 of the time limit relay 328, lead 326, switch 323 of the relay 3H5, leads 325, 324 and 3I2 and also completes the leads 340 through switches 32I by which the motor 322 is setinto operation. The

release of the button 330 as ,by the'handle of the valve control unit completes a circuit through the time limit relay 328, which may be traced as follows: lead 302, switch 3 I3, lead 330, button 300, lead 332, solenoid unit 333 of relay 328, leads 334, 335 and 3I8, emergency switch 3I9 and leads 320 and 3I2. After a predetermined period the solenoid unit 333 opens the switch 32'! and breaks the circuits above described thus bringing the system to rest and restoring the valves to their normal open position.

The subsequent operation of the control unit 25 in dispatching other carriers while the first carrier is in transit resets the time limit relay but does not affect the primary control signal or power circuits other than that the resetting of the relay lengthens the period during which these circuits are maintained.

From the foregoing description it will be apparent that the source of the primary circuits set up by the operators at either station is at station B; that the control and power circuits set up at the dispatching stations are independent of the sources of current at the receiving stations; thatthrowing the handle into the full line pobracket I52.

sition automatically sets the system in operation and simultaneously closes the lower valve and opens the upper valve; that throwing the handle 35 into the dotted line position to close the upper valve and open the lower valve simultaneously sets the time limit relay in operation concomitantly with the beginning of travel of the carrier.

The embodiment shown in Figs. '7, 8 and 9 differs from the embodiment just described in that the upper and lower valves at the terminal are positively opened and closed, no reliance being placed upon the action of the air. As shown in Fig. 7, the terminal I00 comprises a plurality of tube sections terminating in the curved receiving chute IOI which leads to a receiving trough or pan I02. The tube sections I03, I04, I05 and I05 are suitably secured together, and the sections I04 and I03 include the lower and upper valve units I01 and I08 respectively. These units are, so far as the valve construction is concerned, identical, each unit including a plate III), which supports a disk I i I and a shoe I I2, and a. yielding tube I I3 carried by a pin II4 against which the valves rest when in the normal open position.

Secured to the ends of the shaft H5 are links H6 by which the shaft is connected to bars II'I adapted to be raised and lowered by means of a reciprocating element, in the present instance a thrustor I20. It will be understood that one end of each link H6 is keyed to the shaft, so that the motion of the bars is communicated thereto. As shown in Figs. 8 and 9, the thrustor I20 comprises a motor I2I which, through a shaft I22, operates an impeller pump I 23. The shaft I22 is, as shown in Fig. 9, made of two telescoped sections splined to permit relative longitudinal movements. The impeller pump I23 is enclosed within a piston I24, to which is connected a push rod I25, which extends through the casing of the thrustor. Parallel to the push rod I25 is a similar push rod I25 which extends through the easing ports a clevis I28 extending between tongues I29 and secured thereto by a pin I35. The tongues I29 are integral with a bracket I3I suitably secured, as by screws I32, to a yoke I33. The legs of the yoke I33 terminate in the bars Ill previously mentioned and secured thereto are weights $34 which insure the smooth operation of the thrustor. The thruster is supported in a cup I35 carried by, and as here shown, integral with, a bracket I35 mounted upon the section beyond the section including the valve unit controlled by the thrustor. In order to secure the thrustor in position, a clevis I3I extending from the lower end of the thrustor is held by a pin I38 passing through the clevis and the opposite walls of the bracket.

Mounted upon the chute IOI is a valve control unit I53 and an electrical control unit I5I, these units being supported upon a suitably formed The control unit I is similar in every respect to the control unit 25 previously described. Since the alves are operated by the thrustors, it obviously is not necessary that air be conducted from the control unit I 50 to the various valves. However, the pipe I53, which corresponds to the pipe 32, enters the section I05, while the pipe I54 .which corresponds to the pipe 30 enters the section I 03. The valve control unit I50 is thus connected to the source of air by an inlet pipe I54, and to the atmosphere through an outlet pipe I56.

The handle I51 controls the position of the rotor in the unit I50, and 'mounted'upon it is a cam I58, which acts upon reciprocating pin I59 to actuate the electrical control unit I5I in the same manner as the cam 31 actuates the control .unit 26. The control unit I5I is electrically connected through a conduit I60 to one source of supply, and through a conduit I6I to a contactor casing I62 on the upper valve unit, and a contactor casing I63 on the lower valve unit. The contactors within the casings I62 and I63 are normally open, but are adapted to be closed when the valves associated therewith are open.

When a carrier is to be dispatched from a terminal of this type the handle I51 is thrown to the left and the control unit actuated. Through the electrical circuits thus completed as set forth hereinbelow the lower valve unit I01 is closed and at the same time air is supplied under pressure through the pipe I54 to section I03 while section I05 is connected to the atmosphere through pipe I53. The carrier is then introduced into the chute IOI through an open inlet I and descends by gravity .past the open upper valve unit I08. The handle I51 is then thrown to the right whereupon the unit I08 is closed and the unit I01 is opened allowing the carrier to pass into the transit tube by which it is conducted to the other station. At the same time air is supplied under pressure through the pipe I53 to section I05 while-section 103 is connected to the atmosphere through pipe I54. The supply of air to the tube sections concomitantly with the opening and closing of the valve units is essential in order to vent and fill the air spaces above and below the valve units since otherwise the electrically controlled elements would be unable to operate the valves.

The electrical operations will now be described with reference to the wiring diagram in Fig. 10. It is first assumed that an operator at station A desiring to dispatch one or more carriers to station B has thrown the handle I51 to the left thus depressing button 400.

The depression of button 400 at station A completes a pilot circuit traced as follows:

Leads 50I, 502, contactor 503 of upper valve unit, lead 504, contactor 505 of lower valve unit, lead 506, coil 501 of relay 508 (this relay completes the control circuit at station B), lead 509, coil 410 of relay 4II (this relay completes the control circuit at station A), lead 4I2, button 400, lead 4I3, switch 4I4 (normally closed) of relay 408 to a ground. It will be noted that this circuit can not be completed if the contactor of either valve unit at station B" is open which would be the case if either valve were closed and in the path of travel of the carrier.

The control circuit at station A completed by the relay 4 may be traced as follows: lead 4I5, emergency switch 4I6, lead 4I1, lead 4I8, coil MS of starter relay 420 (this relay controls a holding by-pass for the pilot circuit and also completes the power circuit), lead 42I, switch 422 of relay M I, lead 423.

The control circuit at station B controlled by relay 508 advises the operator at that station of the condition of the line and the intent of the operator at station A to dispatch carriers to station B. The circuit thus made is traced as follows: through lead 5I5, emergency switch 5I6, lead 5I1, lead 539, signal 540, lead 54I, switch 542 of relay 508, and lead 523.

The holding by-pass for the pilot circuit above referred to is completed by the energizing of coil 419 of the starter relay 420 previously disclosed. This by-pass acts to maintain the pilot circuit "independent of the position of the button 400 and may be traced as follows: from lead '4I2 through lead 424, switch 425 of the time limit relay 42'6, lead 421, switch 428 of the starter relay 420 to the ground. The starter relay 420 also completes the power circuit for the motor 43I at station A, through leads 429 and switches 430. The lower valve at station A is held closed by 10 the following valve control circuit: from lead 4I1 through lead 432, lower valve actuator 433 (thruster I), lead 434, switch 435 of the valve relay 436, lead 431 and lead 438 to lead 42I. The operator next places a carrier into the chute IOI 15 through the inlet I10 and releases the button 400, which, however, does not break the pilot circuit because of the holding by-pass established as pointed out above. The button 400 now completes circuits through the coil of the valve control relay 436, and through the time limit relay 426 opening the lower valve and closing the upper valve. The valve control circuit may 'be traced from lead 4I1 through coil 443 of the relay 436, lead 444, button 400, lead 445 and lead 438 to lead 421. The time limit relay circuit is completed from lead 444 through lead 446, solenoid unit 441 and lead 448 to lead M1. The energizing of the coil 443 of relay 436 causes the switch 435 to shift from the full line position into dotted 'line position, breaking the circuit previously traced through the lower valve actuator 433 and completing a circuit through the upper valve actuator 450; to wit from lead 4I1 through lead 449, upper valve actuator 450 (a thrustor I20), lead 45I, switch 435 and lead 431 to lead 438.

When the predetermined period has lapsed the time limit relay 426 acts in the usual well known manner the solenoid unit opening the switch 40 425 thus breaking the various pilot and control circuits and opening the upper valve so that the various parts have resumed the position shown in full lines on the drawings and the system is at rest. If, after one carrier has been dispatched and before the time limit relay has acted, the operator 'desires to dispatch a second carrier, this can be done without difliculty by repeating the operation previously described, thereby resetting the solenoid unit 441 so that the motor will continue to operate until after the last dispatched carrier has'arr'ived at station B.

When an operator at station E is to dispatch carriers to station A, the same procedure described above is followed, it being understood, of course, that difierent leads are energized to complete various circuits which will be described briefly without comment. Upon depressing the button 500 a pilot circuit is completed from lead 50I, through lead552, switch 5I4, lead 5I3, button 500, lead 5I2, coil 5I0 of relay 511,1ead553, coil 401 of relay 408, lead 406, contactor 405 of the lower valve unit, lead 404, contactor 403 of the upper valve unit, lead 402 to the ground. The control circuit completed at B is through lead 5 I 5, emergency switch 5I6, lead 511, lead 5I8, coil 5I9 of starter relay'520, lead 52I switch 522 of relay 5I I, to lead 523. The control circuit completed at station A is through lead 4I5, emergency switch 4I6,lead4|1, lead 439, signal 440, lead 44I, switch 442 of relay 408 and lead 460. The holding bypass for the pilot circuit completed at station B is from lead 552 through lead 554, switch 528 of relay520, lead521, switch 525 of time relay 526, and 1ead 52'4to lead 5I2. A power circuit completed at that station is through leads 629 and switches 530 of relay 520, energizing the motor 53 l. The circuits through the'actuators of the upper and lower valve units and through the solenoid unit of the time limit relay will not be traced, it being obvious from an inspection of the drawings that they are identical with the circuits previously described with respect to the dispatching from station A.

The wiring diagram shown in Fig.'1l is similar to that shown in Fig. 10 in that only two wires connect the terminals and the control shown is applicable to the embodiment set forth in Figs. 7, 8 and 9 but since it includes polarized relays it can only be used on direct current service The polarized relay 661 at station A comprises a coil 602, and two groups of switches. One group comprising switches 663, 604 and 665, is actuated when current flows through the relay coil from a source at station B while the other group, comprising switches 666, 66? and 608, is actuated when current flows through the relay coil from a source at station A As shown in the diagram switches 6533, 665, 666 and 66B are normally open and switches 604 and 661 are normally closed. The polarized relay at station 13 is identical in structure and operation with that at station A and' hence will not be described in detail, reference characters beginning at T! being use-d upon the diagram to designate the elements thereof.

The various circuits set up by the control will be described briefly without any detailed discussion of the operation of the system.

When an operator at station A desires to dispatch a carrier to station B the button 666 is depressed thus completing a primary circuit from the positive lead 6 l 6, through lead BI I, switch 664 of polarized relay 66!, lead 6E2, button 66!], lead 6l3, coil 662 of relay 66!, lead 6M, coil 102 of relay lliil, leads H3, and 156, button 100, lead 15], lead H5, switch 567 of relay 16L lead H6, contactor ll! of lower valve unit, lead H8, contactor i it of upper valve unit, lead 126 to the ground.

The relay 661 thus completes a circuitfrom positive lead are through lead 62l, switch 666 of relay 66!, lead 622, lead 623, coil 624 of relay 625 and lead 626 to the ground. The coil 624 when energized closesthe normally open switch 621 of the relay 625 and completes a circuit by which the thrustor I26 of the lower valve unit is caused to close that valve, and which is traced from positive lead 628 of a local control circuit through leads 629 and 660, coil 63! which when energized aetuates the thrustor, lead 632, switch 633 of relay 634, leads 665 and 636, switch 621 and lead 63? to the negative lead 638 of the local circuit. The closure of the switch 621 also completes a circuit from the positive lead 628 through leads 636 and 666, coil 66! of power starter relay 642, leads 643, 635 and 666, switch 621, and lead 631 to the negative lead 663.

The energizing of coil 64! closes the power switches 6% whereby the blower or motor is set into operation, and also closes switch 645 which completes a holding by-pass from lead 622 through switch 665, lead 646, normally closed switch 64'! of the time limit relay 648 and lead 669 to the coil 662, thus insuring the maintenance of the various circuits above described independent of the position of the button 666.

The primary circuit also completes two circuits at station B First, a signal operating circuit which advises the operator at station E that the operator at station A has taken control of the system-andcomprises lead 150 from the positive through which carriers may be dispatched from lead 6m, signal 15L lead 1'52, switch 103 and lead 153 to the ground. Second, a holding by-pass from c-oil H12 which makes the primary circuit independent of the position of the button 106 and comprises lead 154, switch 765, and lead 755 to lead H6 and thence through the contactors H1 and ii iii to the ground.

These circuits having een set up the carrier is introduced into the terminal at station A and the button 600 shifted into the full line position which completes a circuit from lead 649 through leads 6l3 and 656, button 600, lead 651, switch 666, lead 658, coil 65B of relay 634, lead 660 to the ground. The energizing of the coil 659, closes switch 66l and shifts switch 633 into the dotted line position thus completing two circuits, and opening the circuit described above by which the lower valve was closed. One suchcircuit closes the upper valve and comprises lead 629, coil 662 which operates thrustor I26 of that valve unit, lead 663, switch 633, leads 635 and 636, switch 621 and lead 631 to negative lead 638. The other circuit energizes the solenoid unit of the time limit relay 666 from positive lead 628 through lead 639, switch 66L lead 664, solenoid unit 665, leads 635 and 636, switch 627 and lead 637 to negative lead 638. The carrier now passes the lower valve unit and proceeds to the terminal at station B and the circuits set up are maintained until the solenoid unit 665, after a predetermined period, opens the 39 switch 661. Dispatching of other carriers from station A before the switch 641 is opened may be done by repeating the movements of the button 666 previously described. a

When carriers are to be dispatched from station B to station A similar operations are performed and similar circuits set up. These circuits will not be described but since the elements on the wiring diagram at station B have numerals in the seven hundred series corresponding to those in the six hundred series at station A they can be readily traced.

While certain embodiments of the invention have been shown and described it will be understood that we are not limited thereto since changes may be made in these embodiments or other embodiments devised Without departing from the spirit and scope of the invention as set forth in the following claims.

We claim:

1. In a pneumatic dispatch system including two stations, each provided with a terminal, and a transit tube connecting said terminals and either station to the other station, each terminal including a passage forming a continuation of the tube and through which carriers may travel, interlocking valves in said passage, a signal, means at each station for controllingthe operation of the valves and signal, such means including a normally open electrical power circuit, a source of electric current at one station only, and means actuated by said source, which means, when a carrier is to be dispatched from either station, closes the normally open circuit at the dispatching station and permits the control of the valves at that station.

2. In a pneumatic dispatch system includingtwo stations, each provided with a terminal, and 70 a transit tube connecting said terminals and through which carriers may be dispatched from either station to the other station, each terminal including a passage forming a continuation of the tube and through which carriers may travel, in-

terlocking valves in said passage, a signal, means at each station for controlling the operation of the valves and signal, such means including a normally open electrical power circuit, a source of electric current at one station only, and means actuated by said source, which means, when a carrier is to be dispatched from either station, closes the normally open circuit at the receiving station to actuate the signal and thus advise the operator at that station of the intent of the operator at the other station.

3. In a pneumatic dispatch system including two stations, each provided with a terminal, and a transit tube connecting said terminals and through which carriers may be dispatched from either station to the other station, each terminal including a passage forming a continuation of the tube and through which carriers may travel, interlocking valves in said passage, a signal, means at each station for controlling the operation of the valves and signal, such means'including a normally open electrical power circuit, a source of electric current at one station only, and means actuated by said source, which means, when a carrier is to be dispatched from either station, closes the normally open circuits at both stations, whereby the valves at the dispatching station may be controlled and the signal at the receiving station is actuated to advise the operator at that station of the intent of the operator at the dispatching station.

4. In a pneumatic dispatch system including two stations, each provided with a terminal, and a transit tube connecting said terminals and through which carriers may be dispatched from either station to the other station, each terminal including a passage forming a continuation of the tube and through which carriers may travel, interlocking valves in said passage, a signal, means at each station for controlling the operation of the valves and signal, such means including a.

normally open electrical power circuit, a source of electric current at one station only, two wires through which current supplied by said source flows to and from the other station, means actuated by said source including electrically controlled elements at each station, which elements include normally open switches in the station circuits, and a control switch at each station, the closing of which at either station causes the current from said source to actuate the elements and close the switches in the power, circuit at that station, whereby the operation of the valves at that station may be controlled.

5. In a pneumatic dispatch system including two stations, each provided with a terminal, and a transit tube connecting said terminals and through which carriers may be dispatched from either station to the other station, each terminal including a passage forming a continuation of the tube and through which carriers may travel, interlocking valves in said passage, a signal, means at each station for controlling the operation of the valves and signal, such means including, a normally open electrical power circuit, a, source of electric current at one station only, two wires through which current supplied by said source flows to and from the other station, means actuated by said source including electrically controlled elements at each station, which elements include normally open-switches in the station circuits, and a control switch at each station, the closing of which at either station causes the current from said source to actuate the elements and close the switches in the power circuit at the other station, to actuate the signal at that station, whereby to advise the operator of the intent of the operator at the first-named station.

6. In a pneumatic dispatch system including two stations, each provided with a terminal, and a transit tube connecting said terminals and through which carriers may be dispatched from either station to the other station, each terminal including a passage forming a continuation of the tube and through which carriers may travel, interlocking valves in said passage, a signal, means at each station for controlling the operation of the valves and signal, such means including a normally open electrical power circuit, a source of electric current at one station only, two wires through which current supplied by said source flows to and from the other station, means actuated by said source including electrically controlled elements at each station, which elements include normally open switches in the station circuits, and a control switch at each station, the closing of which at either station causes the current from said source to actuate the elements and close the switches in the power circuit at each station whereby the operation of the valves at that station may be controlled and the signal at the other station is actuated to advise the operator of the intent of the operator at the first-named station.

'7. In a pneumatic dispatch system including two stations, each provided with a terminal, and a transit tube connecting said terminals and through which carriers may be dispatched from either station to the other station, each terminal including a passage forming a continuation of the tube and through which carriers may travel, interlocking valves in said passage, a signal, means at each station for controlling the operation of the valves and signal, such means including a normally open electrical power circuit, a source or" electric current at one station only, two wires through which current supplied by said source flows to and from the other station, means actuated by said source including electrically controlled elements at each station, which elements include normally open switchesin the station circuits, and a control switch at each station, the closing of which at either station causes the current from said source to actuate the elements and close the switches in the power circuit at that whereby the power circuit is thereafter maintained independent of the control switch.

8. In a pneumatic dispatch system including two stations, each provided with a terminal, and a transit tube connecting said terminals and through which carriers may be dispatched from either station to the other station, each terminal including a passage forming a continuation of the tube and through which carriers may travel, interlocking valves in said passage, a signal, means at each station for controlling the operation of the valves and signal, such means including a normally open electrical power circuit, a source of electric current at one station only, two wires through which current supplied by said source flows to and from the other station, means actuated by said source including electrically controlled elements at each station, which elements include normally open switches in the station circuits, and a control switch at each station, the closing of which switch at either station causes the current from said source to actuate the 7 5 elements and close the switches in the power circuit at the other station to actuate the signal at that station, whereby to advise the operator of the intent of the operator at the first-named station and to short circuit the control switch of that station, whereby the power circuit is maintained independent of the control switch.

9. In a-pneumatic dispatch system including a station terminal and a transit tube through which carriers may be dispatched, said terminal including a passage which forms a continuation of the tube and through which carriers travel, interlocking valves which open and close said passage, electrically operated means for closing and opening said valves, means for creating a flow of air through said tube, and -a control device by which said electrically operated means are actuated seriatim and said flow-creating means is set into operation.

10. In a pneumatic dispatch system including a terminal and a transit tube leading therefrom, said terminal having a passage forming a continuation of said tube and by which carriers to be dispatched travel to said tube, two valves in said passage, either of which valves when closed prevents the travel of carriers through the passage, means for operating said valves independently,

' means for creating a flow of air through said tube,

a control device including a movable member which in one position sets said flow-creating means in operation and causes said operating means to close one valve and open the other valve, and in another position closes the other valve and opens the first valve, the status of the flow-creating means being independent of the member in this position, and means for diverting a part of the air flow into the passage in advance of whichever valve is being closed.

11. In a pneumatic dispatch system including a terminal and a transit tube leading therefrom, said terminal having a passage forming a continuation of said tube and by which carriers to be dispatched travel to said tube, two valves in said passage, either of which valves when closed prevents the travel of carriers through the passage, means for operating said valves independently, means for creating a flow of air through said tube, a control device including a movable member which in one position sets said flowcreating means in operation and causes said operating means to close one valve and open the other valve, and in another position closes the other valve and opens the first valve, the status of the flow-creating means being independent of the member in this position, and means for diverting a part of the air flow into the passage in advance of whichever valve is being closed, and for venting the passage behind that valve.

12. In a pneumatic dispatch system including two stations, each provided with a terminal, and a transit tube connecting said terminals and through which carriers can be dispatched from either station to the other station, the terminal at each station including a passage which forms a continuation of said tube, two interlocking valves which when closed'prevent the travel of carriers through the passage, an electrical contactor associated with each valve, an electrical power circuit at each station, relays comprising switches in said circuit and coils which when energized hold said switches in a predetermined position, and a primary circuit at each station from a source of current at one station only, each primary circuit including a normally open switch at and the contactors of the valves at the other station, each of which contactors opens the circuit when the valve associated therewith is closed and closes the circuit when the valve associated therewith is open, the completion of the primary circuit at either station by the closure of the switch thereat acting, when the valves in the terminal of the other station are open, to energize the relay coils, thereby causing the relay switches to 'close the power circuit at the selected station, whereby the valves at that station may be operated and a carrier be dispatched therefrom.

13. In a pneumatic dispatch system including two stations, each provided with a terminal, and a transit tube connecting said terminals and through which carriers can be dispatched from either station to the other station, the terminal at each station including a passage which forms a continuation of said tube, two interlocking valves which when closed prevent the travel of carriers through the passage, an electrical contactor associated with each valve, an electrical power circuit at each station, relays comprising switches in said circuit and coils which when energized hold said switches in a predetermined position, a primary circuit at each station from a source of current at one station only, each circuit including a normally open switch at one station, the coils of relays at each station and the contactors of the valves at the other station, each of which contactors opens the circuit when the valve associated therewith is closed and closes the circuit when the valve associated therewith is open, the completion of the primary circuit at either station by the closure of the switch thereat acting, when the valves in the terminal of the other station are open, to energize the relay coils, thereby causing the relay switches to close the power circuit at the selected station, whereby the valves at that station may be operated and a carrier be dispatched therefrom, and a time limit relay at each station energized when the station switch is reopened and caused to break the primary and power circuits thus established after a predetermined interval.

14. In a pneumatic dispatch system including a terminal and a transit tube leading therefrom, means for creating a flow of air through said tube, said terminal having a passage forming a continuation of said tube and by which carriers to be dispatched travel to said tube, two normally open valves in said passage, either of which valves when closed prevents the travel of the carriers through the passage, an electrically operated mechanism associated with each valve for opening and closing the same, each mechanism being operable independently of the other, and a control device including a movable member which, in one position sets the flow-creating means in operation and causes the mechanism associaied with one valve to close such valve, and, in another position causes the first-named mechanism associated with the other valve to close such valve, the status of the flow-creating means being unaffected by the member in the last-named position.

15. In a pneumatic dispatch system including a terminal and a transit tube leading therefrom, means for creating a flow of air through said tube, said terminal having a passage forming a continuation of said tube and by which carriers to be dispatched travel to said tube, two normally open valves in said passage, either of which valves when closed prevents the travel of the carriers through the passage, an electrically operated ing and closing the same, each mechanism being operable independently of the. other, a control device including a movable member which, in one position sets the flow-creating means in operation and causes the mechanism associated with one valve to close such valve, and, in another po-'- sition causes the first-named mechanism associated with the other valve to close such valve, the status of the flow-creating means being unafiected by the member in the last-named position, and means controlled by said member for diverting a part of the air low into the passage in advance of whichever valve is being closed.

16. In a pneumatic dispatch system including a terminal and a transit tube leading therefrom, means for creating a flow of air through said tube, said terminal having a passage forming a continuation of said tube and by which carriers to be dispatched travel to said tube, two normally open valves in said passage, either of which valves when closed prevents the travel of the carriers through the passage, an electrically operated mechanism associated with each valve for opening and closing the same, each mechanism being operable independently of the other, a control device including a movable member which, in one position sets the flow-creating means in operation and causes the mechanism associated with one valve to close such valve, and, in another position causes the first-named mechanism associated with the other valve to close such valve, the status of the flow-creating means being unaffected by the member in the last-named position, and means controlled by said member for diverting a part of the air flow into the passage in advance of whichever valve is being closed and for venting the passage behind such valve.

17. In a pneumatic dispatch system including a station terminal, a transit tube through which carriers are dispatched and means for creating a carrier dispatching flow of air through the tube, said terminal including a passage which forms a continuation of the tube and through which carriers travel to or from the tube, valves which open and close said passage, mechanism for opening and closing each of said valves independently, means for operating said mechanism and a control unit by which said flow creating means is set into operation, said unit including movable means which in one position causes said mechanism operating means to close one valve and in another position causes said mechanism operating means to close the other valve, the status of the flow creating means being unaffected by the movement of said means from one position tothe other.

18. In a pneumatic dispatch system including a station terminal, a transit tube through which,

mechanism associated with each valve for open position causes said first named unit to operate the mechanism of one valve and inanother position causes said first named unit to operate the mechanism of the other valve, the status of the flow creating means being unaffected by the ;movement of said means from one position to the other.

19, In a pneumatic dispatch system including two stations, each provided with a terminal at which carriers may be received and from which carriers may be dispatched, a transit tube connecting said terminals and through which carriers may be dispatched from either station to the other station, and means for creating a carrier impelling flow of air in the transit tube, each terminal including a passage forming a continuation of the tube and through which carriers may travel, interlocking valves in said passage and a signal, means at each station for controlling the operation of the flow creating means, the valves and the signal thereat, such means including normally open electrical circuits, and a source of electrical current therefor, and means for closing said circuits comprising a source of electrical current at one station only, a normally open primary circuit supplied from said source, controls at both said stations for said primary circuit, and means at both stations actuated by said primary circuit, for closing the normally open circuits thereat so that, when a carrier is to be dispatched from either station, the actuation of the control of the primary circuit at that station causes the means actuated by the circuit to close the normally open circuits controlling the flow creating means, and valves at the dispatch station and the normally open circuit controlling the signal at the receiving station.

20. In a pneumatic dispatch system including two stations, each provided with a terminal at which carriers may be received and from which carriers may be dispatched, a transit tube con.- necting said terminals and through which carriers may be dispatched from either station to the other station, and means for creating a carrier impelling flow of air in the transit tube, each terminalv including a passage forming a continuation of the tube and through which carriers may travel, and a signal, means at each station for controlling the operation of the flow creating means and the signal, such means including normally open electrical circuits, and a source of electrical current therefor, and means for selectively closing said circuits comprising a source of electrical current at one station only, a normally open primary circuit supplied from said source, controls at both said stations for said primary circuit and means at both stations actuated by said primary circuit for closing the normally open circuits thereat so that when a carrier is to be. dispatched from either station, the actuation of the control of the primary circuit at that station causes the means actuated by the circuit to close the normally open circuit controlling the flow creating means at the dispatch station and the normally open circuit controlling the signal at the receiving station.

CHESTER S. JENNINGS. FRANK W. NIACMARTIN. 

